Flexible plastic medical containers are often used in the medical field, for example to contain and receive various sterile solutions, dialysis solution, whole blood, plasma, etc. An example of a well-known flexible plastic medical container is the Viaflex.RTM. flexible vinyl container, sold by Baxter Travenol Laboratories, Inc.
In manufacturing the flexible plastic containers, webs of sheet material are cut and heat sealed, with the ports being interposed at one end of the container and the webs being heat sealed around the ports. One prior art method and apparatus for producing flexible plastic medical containers is disclosed in British Pat. No. 1,553,244.
There is a significant problem in providing automated machinery for manufacturing flexible plastic containers in which the port is a closed port. A "closed port" is a port in which the port is not open from one end to the other. For example, a port having a transverse pierceable membrane therein would be considered a "closed port", as would a port that is covered with a tab or the like to close one end thereof. Flexible plastic containers which are used for containing, collecting and/or storing blood or blood plasma typically utilize a pair of closed ports at one end thereof, with each of the closed ports comprising a port having a transverse pierceable membrane and a pair of tabs sealed over the distal end of the port to prevent access to the port until the tabs are pulled away from each other.
The significant problem in providing automated machinery for such flexible plastic bags with closed ports results from the fact that a mandrel located at one side of the container cannot readily be utilized to insert the closed port into one end of the container whereupon heat sealing will occur. Since a closed port inherently contains some blockage, a mandrel which is intended to enter the container from the outside cannot place the closed port in position for heat sealing and also allow the sealing to occur over the mandrel. Thus it has been found necessary for the production of flexible plastic bags having closed ports to require a significant number of manual steps, in order for the mandrel to cooperate with both the web material for the container and the closed ports during heat sealing.
Flexible plastic blood containers may also include a donor tube, which comprises an elongated tube having a code designation imprinted repeatedly along the tube. When blood is collected in the container, the blood which is contained within the donor tube may be removed for testing by sealing off portions of the donor tube. The code number will be used to identify the particular sample as being from a particular donor.
In automating the manufacture of flexible plastic blood containers, it is most efficient if the cutting and connecting of the donor tube to one end of the container can be part of the automatic process, together with the connecting of the closed ports to that end of the blood container. It is particularly important, however, that the cutting of the donor tube be accurate, because it is mandatory that all of the code numbers along the donor tube be identical to each other and that the donor tube have a precise, predetermined length.